Sound film and method of making same



Oct. 18, 1932. H, c p 1,883,559

SOUND FILM AND METHOD OF MAKING SAME Filed Nov. 5, 1928 llllllllllllll 1-'1 INVENTOR (.CZT1M 42:. ATTORNEY Patented Oct. 18,. 1932 UNITED STATES PATENT; OFFICE.

HARRY E. CHIPMAN. OF SPRINGFIELD, MASSACHUSETTS, ASSIGNOR, BY DIRECT AND MESNE ASSIGNMENTS, TO ANDREW LE BOY CHIPMAN, OF NEW YORK, N. Y.

SOUND FILM AND METHOD OF MAKING SAME Application filed November 5, 1928. Serial No. 317,289.

This inventionrelates generally to sound film and more particularly to motion picture film having one or more lines of magnetic sound recording material fixedly and perma- 5 nently secured thereto. This invention is also concerned with an efiective method and means for producing the sound film cheaply and in quantities.

Motion picture film generally in use possesses expansive characteristics peculiar to itself. Changes in temperature or moisture conditions as well as external force exerted on the film, have their corresponding efifects on the character and size of the film. For

5 these reasons and for the added reason that the film surfaces are glossy and smooth, it is difiicult to effectively and permanently secure any sound record to the film body, and particularly sound records having difierent g0 expansion coefficients than the film itself. The problem is rendered still more difficult because of the bending and twisting strains and general rough handling which the film undergoes during use, all tending to loosen and separate the sound record from the film. Furthermore, the talking record must be so secured to the film body that its sound recording and reproducing qualities are in no wa impaired.

n object of this invention is to provide a sound film having the sound record secured to the film body in a lasting and permanent manner without impairment of the sound qualities of the record.

Another object of this invention is to provide a sound film comprising a magnetic sound record permanently secured to a film body in such a manner as not to render the sound film unduly bulky 0r unwieldy.

Another object of this invention is the production of a sound film having the magnetic sound record directly associated with the film body, the sound record being of such a character that it will readily expand or contract with the film, and so secured to the film that it will not become unloosened or detached therefrom after long continued hard usage.

Still another object of this invention is to devise a method of securing a sound record or records to a film body permanently and securely and in a rapid and efl'ective manner.

Still another object of this invention is to devise a method and means for making sound film, which consists generally of means and devices for permanently securing sound record material to a film body securely and effectively and which will enable the manufacturer to produce said film rapidly and at low cost. I

Other objects of this invention will be in part obvious and in part pointed out as disclosure proceeds.

My invention is concerned with the production of sound film and more particularly sound film of the character having a strip or strlps of some magnetizable material secured 'to the body of the film. l have found that granular magnetic material such as iron filings readily retain magnetic impressions corresponding to sound vibrations. The ad vantage of using granular magnetic mate rial resides in the fact thata strip or pile of granuiar magnetic material will readily expand and contract with the film body without producing undue strain in and on the film. Difficulty, however, is encountered in securing granular material to the film body in such a manner that the granules will not be rub-bed 05 or their relative position distfilirbed during the handling or bending of the My sound film consists of a strip or strips of granular magnetic material positioned lengthwise along the film. A coating of glue or cementitious material is first placed upon the film body in which the magnetic granules are embedded. A covering or coating of cementitious material is then placed continuously over the strip or pile of magnetic material in such a manner as to overlap on to the film and thus, in efiect, pocket the magnetic granules between the outside cementitious covering and the film. The cementi- 95 tious material may be flowed or brushed into position on the film while in a-liquid condition, but is preferably of such a nature that it remains hard and solid at ordinary temperatures. The cementitious material may no inventlon. v

Referring to the drawing, Fig. 1 is an apparatus or making my sound film;

Fig. 2 1s a face view of my sound film with .certain fragments broken away to illustrate f t e more clearly the structure 0 film;

Fig. 3 is an enlarged fragmentary cross sectional view of my apparatus, taken on line 33 of Fig. 1;

Fig. 4 is an enlarged fragmentary cross sectional view of my sound film taken on line 44 of Fig. 2;

Fig. 5 is an enlarged fragmentary cross sectional view of a sound film of modified construction.

Similar reference characters refer to similar parts throughout the several views of the drawing.

Referring more particularly to Figs. 2 and 4, my sound film generall" comprises the usual film body 1 having t e photographic emulsion coating or coatings. Incorporated with this film body is the sound record 2 consisting of a strip of magnetizable material, preferably of granular form. Hardened steel filings are excellent for the purpose, althou h other granular magnetic material may e used within the contemplation of this invention. The magnetizable granules or particles are placed upon the film body in a continuous line and in such a manner as not to interfere with the taking of the picture on the film.

To permanently and immovably secure the magnetic granules or particles to the film body, a strip of cementitious material 3 is first coated onto the film body. The magnetic articles 2 are sprinkled over and embedded 1n this cementitious strip in a smooth and even layer. I preferably incorporate two sound strips of magnetizable material to each strip of film as shown in Fig. 2, a sound strip being positioned at each side of the film, between the sprocket holes 4 and the picture area. However, only one sound strip may be used, as shown in Fig. 5, and the sound strip or strips may be secured in various positions on the film where they will not interfere with the taking of the picture within the contemplation of my invention.

A layer of cementitious material 5 is now placed over the magnetic particles. This cementitious layer is in the form of a continuous strip of such width as to cover the particles and overlap on to the film body, adhering thereto, and thus pocket the particles between this cementitious layer and the film body. A drying or cooling operation may then be necessary to harden this cementitious layer. A second cementitious layer 6 may be placed over the first and of such width as to overlap on to the film body, adhering to the same. The magnetic particles 2 are thus in effect embedded or cast into the upper and lower layers of cementitious material and are in addition pocketed within the surrounding cementitious layers and the film body. The relation between the particles cannot thus be disturbed and they are held permanently and securely to the film.

The cementitious material is preferably applied in a fluid or semi fluid condition and should be of such, a character as to harden and solidify into a strong and tough material upon cooling or drying. It is necessary that the cementitious layers covering the magnetic particles be hard, to Withstand wear, and.

tough, so that cracks will not form in the same. This cementitious material may be composed of practically the same ingredients as that of the film body, and may be applied to the film body in a semi fluid or molten condition. When solidified these cementitious layers will assume the characteristics of the film body, possessing the same appearance, hardness, toughness, bending and expansion characteristics.

I have discovered that magnetic lines of force, when suitable coils are used and the proper voltage is applied, will travel through film material and cementitious layers generally without hindrance or interruption. The magnetic particles pocketed within the cementitious layers can readily be magnetized to produce thedesired sound record by pass ing the sound strip covered with cementitious layers under the magnetizing pole piece. Reproduction of the sound recorded in the magnetic material is not interfered with by the superimposed cementitious layers.

The magnetic particles should be well compacted together and laid in an even strip for most effective sound recordation and reproduction. It is not necessary that the sound strip have great thickness or breadth, this being largely dependent upon the fineness of the magnetic particles. Since my sound strip secured to the film comprises individual particles compacted together, no external strains are exerted on the film body due to different expansion coefiicients of the sound strip and film body. For the same reason there is less tendency for the sound strip to loosen from the film body.

In Fig. 1 I show an apparatus for making my sound film. The film strip 1 is fed from reel 7 and is drawn through the guide rollers 8, 9 and 10 by suitable mechanism such as a sprocket 11. A pressure roller 12 may be provided to keep the film strip in operative engagement with the sprocket. One or more cement pets 13 containing the cementitious substance are suitably supported over tain a uniform layer.

the film strip and are each provided with a suitable nozzle or dispenser for coating the strip 3 of the cementitious substance on the advancing film.

A corresponding number of receptacles 15 which contain the magnetic particles or iron filings, are provided. Each receptacle is provided with a feed spout 16 which conducts the magnetic particles in an even layor over the glue strip 3. The feed spout may be provided with a suitable valve 17 by means of whichthe flow of magnetic material to the film may be controlled. Each container may also be equipped with a suitable vibrator or other mechanism for insuring a steady flow of the magnetic particles on to the film strips. For this purpose I suspend the container 15 from a rod 18 or other suitable means. An electric vibrator represented at 19 is provided having a vibrating arm 20, pivotally secured to the container. It is seen that by this apparatus the container may be rocked or vibrated rapidly to and fro through a small angle, causing the magnetic particles to flow in a steady and uniform stream to the film.

Another film advancing sprocket 21 and cooperating roller 22 may be provided to aid in advancing the film through the remaining devices of my apparatus. Following the container 15 another set of cement pots 23 are provided. These pots are provided. with suitable dispensers 24 for. placing the layer 5 of the cementitious material over the strip of magnetic material This cementitious layer should be of such a width as to completely cover the magnetic strip and overlap each side thereof, adhering to the film body. The dispensers 24 must be of such shape as to lay a uniform layer of the cementitious material of the above width and must be raised above the magnetic strip so as not to disturb the particles. The cementitious material may be forced through the dispenser under regulated pressure if necessary to ob- A suitable valve 25 may be provided for controlling the flow.

In order that the magnetic particles be concentrated into a uniform strip and held in position prior to covering the same with the cementitious layer, a suitable magnet 26 may be provided, positioned under the film and extending from each feed spout 16 and well beyond the dispenser 24. Magnets 26 aid in obtaining a uniform flow of magnetic particles from the receptacles 15 to the film strip, concentrate the particles into uniform and compact strips and further retain the particles against movement until they have been covered and fixed in position by an overlying cementitious layer.

The film strip may then be run over guide rollers 27 and 28 and partially dried through contact with the air. Drying of the cement cannot be forced as this would cause the film to buckle and curl. The cementitious material generally dries quickly and should be dried sufiiciently so that it is no longer sticky and yet plasticwhen it reaches the second set 0 cooperating pressure rollers 29 and 30. These rollers operate to compact the magnetic particles together andpress the plastic overlying cementitious layer firmly to the film. The fihn strip is then conducted over guide rollers 31 and 32 and under a third series of cement pots 33. These cement pots maybe provided with nozzles or dispensers 34 similar to those associated with glue pots 13 and23.

Nozzles 34 lay a second layer 6 of cementitious material over each of the layers 5 of such a width as to completely cover the same and overlap onto the film body, adhering thereto. The film then passesover guide roller 35 and is generally drawn through this portion of the apparatus by the sprocket wheel 36 and cooperating pressure roller 37. The completed film is then spirally wound up upon a large drying drum 38 where it is exposed to the drying action of the air. The film is placed on the drying drum in a flat condition and the drum is given a slow translatory movement as it rotates causing the film to spirally wind thereon in such a manner that the film strips do not overlap one another. The construction and operation of this drum is describe-d in my copending application Serial No. 698,588 filed March 12,1924.

To expedite manufacture, reel 7 and drum 38 may be of such size as to carry a wide sheet of film material. The various cement pots, containers, magnets, dryers, etc. may then be duplicated or enlarged so as to lay a number of the sound strips, properly spaced, on the film sheet. The sheet is then properly cut into film strips of proper width and the sprocket holes made therein.

Thus it is seen that I have produced a sound film comprising a film body carrying magnetic sound material which is rugged and adapted to withstand hard service. My sound strips comprising magnetizable particles, pocketed and held to the film body as above described, record and reproduce sounds with the greatest precision and accuracy. The more diificult sounds produced by the speaking voice, such for example as words containing th and S are faithfully recorded and reproduced. I have also disclosed a method and apparatus for producing my sound film rapidly, and in quantities.

As many changes could be made in the above construction, and as many apparently widely diflerent embodiments of this invention could be made without departing from the scope thereof, it is intended that all matter contained in the above description or shown in the accompanying drawing shall be interpreted as illustrative and not in a limiting sense.

What I claim is p v A sound film of the character described, in-

eluding a film body a plurality of strips of cementitiousmaterial coated on said film body, magnetic particles comprising the sound record embedded in said cementitious material, and a plurality of layers of cementitious material extending over said magnetic particles and each overlapping on to the film body to permanently secure the particles to. I the film and to rotect the same against disturbance and in ury.

This specification signed and witnessed this'23rd day of October; 1928.

- HARRY E.' CHIPMAN. 

